A metal catalyst such as platinum or manganese dioxide has been used as a catalyst for decomposing hydrogen peroxide contained in a solution. It has also been proposed that activated carbon subjected to an activating treatment or activated carbon activated and caused to carry platinum be used for the decomposition of hydrogen peroxide (for example, Patent Literatures 1 and 2).
Meanwhile, a Fenton method involving adjusting the pH of waste water to an acidic value, and adding hydrogen peroxide and an iron(II) compound has been employed as a method of treating waste water.